WO2021063867A1 - Closing unit and blow-moulding tool for a blow-moulding machine - Google Patents

Abstract

The invention relates to an assembly comprising a closing unit (1) for a blow-moulding machine having a first and second mould carrier (5), and comprising a blow-moulding tool which is arranged on the closing unit (1) and which has two tool halves, wherein a mould lower part of each tool half (2, 3) is movable back and forth with respect to the mould upper part of each tool half (2, 3) in a second direction of movement (18), which is different from a first direction of movement (17), between an open state and a closed state by means of at least one first and at least one second actuator, and, in the closed state of the two tool halves, the blow-moulding tool delimits a mould cavity with undercuts when the two mould lower parts are likewise in the closed state. In order to develop the assembly consisting of closing unit (1) and blow-moulding tool to the effect that the mould clamping region of the blow-moulding tool is not restricted by the actuators and at the same time the costs for blow-moulding tools are reduced and the change of the blow-moulding tool is simplified, it is proposed that the actuators, such as for example hydraulic cylinders, are not arranged on the blow-moulding tool itself as was hitherto the case, but on the closing unit (1), and are configured such that they can be coupled to the mould lower part.

Description

Clamping unit and blow molding tool for a blow molding machine

The invention relates to a closing unit for a blow molding machine with a first and second mold carrier and a blow molding tool with two tool halves arranged on the closing unit, each tool half being releasably attached to one of the two mold carriers and having an upper mold part and a lower mold part, the two tool halves between an open state and a closed state can be moved back and forth in a first direction of movement, the lower mold part of each tool half with respect to the upper mold part of each tool half in a second direction of movement different from the first direction of movement between an open state and a closed state by means of at least one first and at least one second actuator is movable and the blow molding tool in the closed state of the two tool halves delimits a mold cavity with undercuts when the two lower mold parts are also in the closed state.

The invention relates to the production of hollow bodies by means of blow molding, in particular the production of containers made of plastic, such as canisters or bottles, for example. In the production of such hollow bodies by blow molding, for example, an extruder with a Blow head is a tubular preform that is enclosed by the blow molding tool and expanded by means of a blow mandrel introduced by compressed air in such a way that the hollow body in question has the inner contour of the blow molding tool. The two tool halves can generally be moved against one another in the horizontal direction by means of a closing unit in order to open or close the blow molding tool. The structure of such a locking unit is disclosed, for example, in DE 102012 109 499 A1.

In practice, the containers to be produced can have depressions on the lower and / or upper side, for example to form a curved container base or a grip area. The depressions represent an undercut compared to a lateral demolding of the container from the tool halves. For this reason, two-part tool halves of a blow molding tool are known from the prior art, the lower bottom half of which can be lowered relative to an upper mold part of the tool half. To remove the container from the mold, the lower bottom half of each tool half is lowered separately via at least one hydraulic cylinder and then raised again for a new production cycle of a container.

In a first blow molding tool used in practice, two hydraulic cylinders are attached to the side of the upper mold part on a frame of the tool half and connected to the bottom half on the output side via the piston rod. In the case of a second blow molding tool used in practice, only a hydraulic cylinder is on the frame of the tool half below the lower bottom half attached and connected on the output side via the piston rod to the underside of the bottom half.

The disadvantage of the first blow molding tool is that two actuators are required per tool half and the overall width of the blow molding tool resulting from their arrangement can cause problems. In the case of the second blow molding tool, it is not possible to change the blow molding tool from the side.

US Pat. No. 5,026,268 A discloses a blow molding system for the simultaneous blow molding of two plant pots, the edge areas of which are compression molded. Each tool half of the blow molding tool has a total of five molded parts. The two lower and upper mold parts of each mold half are rigidly connected to one another and in turn rigidly attached to a base of the respective mold half. This base is part of the blow molding tool and forms the frame of each of the two tool halves. A hydraulic cylinder is attached to this frame of the blow molding tool and is connected to the two lower mold parts via a piston rod. The firmly interconnected lower mold parts of each mold half are movable relative to a mold part lying between them in the direction of a guide rod connecting the mold parts. The intermediate molded part is movable relative to the two upper molded parts firmly connected to the base of each mold half in the direction of a further guide rod. This relative movement allows the edge area of the two planters to be molded. Based on this prior art, the invention is based on the object of developing an arrangement of clamping unit and blow molding tool in such a way that the actuators do not restrict the clamping area of the blow molding tool, at the same time reducing the costs for blow molding tools and simplifying changing the blow molding tool.

The solution is based on the idea of arranging the actuators, such as, for example, hydraulic cylinders, not on the blow molding tool itself, as was previously the case, but on the clamping unit and designing it to be couplable with the lower part of the mold.

In particular, the object is achieved in a closing unit of the type mentioned in that the at least one first actuator and the at least one second actuator are arranged on the closing unit and one of the two lower mold parts is detachable with an output of the at least one first actuator and the other of the two lower mold parts is releasably connected to an output of the at least one second actuator.

According to the invention, the actuators become part of the closing unit of the blow molding machine and remain on the closing unit when they are changed. When using several blow molding tools in the blow molding machine, only one set of actuators is required. Due to the releasable connection between each actuator and one of the two lower mold parts, changing the blow molding tool is simplified. At the same time, the space required for the blow molding tools is reduced. The actuators can be positioned on the machine side in a space-optimized manner in a space that is not or only partially usable for the blow molding tool. The actuators are preferably arranged below the lower mold parts and releasably connected to the underside of the respective lower mold part.

If the at least one actuator is arranged below the lower mold part and can be detachably connected to the underside of the lower mold part, this can be done

Remove the blow molding tool laterally, i.e. transversely to the closing direction of the two tool halves, from the clamping unit.

The at least one first actuator and the at least one second actuator are arranged on the closing unit so that they can move relative to one another in the first direction of movement.

In order to be able to operate the actuators already during the movement of the mold halves in the first direction of movement, a preferred embodiment of the invention provides that the at least one first actuator moves synchronously with the first mold carrier and the at least one second actuator moves synchronously with the second Mold carrier moves.

To synchronize the movement, in one embodiment of the invention the at least one first actuator can be arranged directly on the first mold carrier and the at least one second actuator can be arranged directly on the second mold carrier. A fastening bracket for indirect fastening of the at least one first actuator and a fastening bracket for the second mold carrier can be attached to the first mold carrier be arranged indirect fastening of the at least one second actuator.

In order to synchronize the movement, a further embodiment of the invention provides that the at least one first actuator and the at least one second actuator are movably arranged on the clamping unit along at least one stationary longitudinal guide, a first coupling the movement of the first mold carrier on the at least one first Actuator and a second coupling that transmits the movement of the second mold carrier to the at least one second actuator.

A coupling rod or a carrier element can be used as a coupling, for example.

A stationary guide present on the closing unit can be used as the stationary longitudinal guide for the actuators, along which the first and second mold carriers are also displaceably guided. Alternatively, a separate stationary longitudinal guide is provided for the actuators.

A defined interface for power transmission is created by means of the releasable connection between the actuator and the lower part of the mold. In order to be able to quickly release and restore the connection between the actuator and the lower mold part, the releasable connection is designed as a coupling in an advantageous embodiment of the invention, which is used for the transmission of forces between the actuator and the lower mold part at least in the second Direction of movement, that is to say perpendicular to the horizontal closing and opening movement of the two tool halves.

In the interest of automating the coupling process, the coupling is preferably designed as a switchable, non-positive or positive coupling, for example as an electromagnetic coupling.

The actuators are set up in such a way that they can move the lower mold part linearly to and fro in the second direction of movement between the open state and the closed state. The actuators can be designed as linear drives, in particular as fluid-operated working cylinders. Alternatively, the actuator is a crank mechanism that converts a rotary movement into an oscillating thrust movement in the second direction of movement.

The second direction of movement of the lower mold parts is usually perpendicular to the first direction of movement for opening and closing the blow molding tool, but can also run at a different angle depending on the hollow body to be produced.

The invention is explained in more detail below with reference to the figures. Show it

Figure 1 is a side view of a first embodiment of a clamping unit for a blow molding machine,

FIG. 2 shows a longitudinal section through the clamping unit according to FIG. 1, Figure 3 is a perspective view of the locking unit according to Figure 1,

FIG. 4 shows a side view of a second embodiment of a clamping unit for a blow molding machine,

FIG. 5 shows a plan view of the locking unit according to FIG

4,

Figure 6 is a perspective view of the locking unit according to Figure 4,

FIG. 7 shows a side view, partially broken away, of a second embodiment of a closing unit for a blow molding machine,

Figure 8 is a plan view of the locking unit according to Figure 7 and

FIG. 9 is a perspective view of the locking unit according to FIG. 7.

With regard to the structure of the clamping unit (1) of the present invention, in particular the common drive for moving the mold carriers back and forth, the base frame with guides arranged thereon, the U-shaped frame elements and the synchronizing device, reference is additionally made to DE 10 2012 109 499 A1 taken.

Figures 1 - 3 show a first embodiment of the clamping unit 1 for a blow molding machine with a blow molding tool with two tool halves (2,3), each tool half (2,3) having an upper mold part (2.1, 3.1) and a lower mold part (2.2, 3.2) having. The tool half (2) is releasably attached to a first mold carrier (4) and the tool half (3) to a second mold carrier (5). The first mold carrier (4) is articulated to the two frame elements (6) of the closing unit (1). The second mold carrier (5) is connected to a drive (7) for moving the two mold carriers (4,5) back and forth and thus the tool halves (2,3), the drive (7) also being supported on the frame elements (6).

The closing unit (1) has a base frame which has side cheeks (9) which are arranged parallel to one another and at the upper edge of which a longitudinal guide (8) is arranged. The first and second mold carriers (4, 5) and the drive (7) are connected to guide elements which are slidably arranged on the longitudinal guides (8). A synchronizing device (10) is also arranged on the base frame of the clamping unit (1), by means of which the closing and opening movement of the two mold halves (2, 3) takes place symmetrically in a first direction of movement (17).

Figures 1-3 show the two tool halves (2, 3) in an open state. The lower parts of the mold (2.2, 3.2) are also in an open state. In the closed state, the two mold halves (2,3) and the respective upper and lower parts of the mold (2.1, 2.2 and 3.1, 3.2) rest against one another and delimit a mold cavity for producing a hollow body, in particular a canister.

A fastening bracket (11, 12) is attached to the underside of the first mold carrier (4) and the second mold carrier (5). A first actuator (13) or a second actuator (14) is fastened to each fastening bracket (11, 12) below the lower mold part (2.2, 3.2). The first actuator (13) is via a switchable coupling (15, 16) and the second actuator (14) can each be releasably connected to the underside of the associated lower mold part (2.2, 3.2).

By means of the actuator (13, 14), designed as a linear drive, for example, the lower mold parts (2.2,3.2) can be moved vertically in a second direction of movement (18) in relation to the upper mold parts (2.1,3.1) of the two tool halves (2,3) to move the lower mold part (2.2, 3.2) of each tool half (2,3) to and fro with respect to the upper mold part (2.1) of the respective tool half (2,3) between an open state and a closed state. The second direction of movement (18) runs perpendicular to the first direction of movement (17).

From Figure 2 it can be seen that both the two upper mold parts (2.1,3.1) and the two lower mold parts (2.2,3.2) have mold areas which are designed to form depressions on the bottom and top of the hollow body to be produced. These mold areas require the lower mold parts (2.2, 3.2) to be brought into an open state by means of the actuators (13, 14) before the hollow body is removed from the mold.

Due to the arrangement of the actuators (13, 14) in the space between the frame elements (6), the mold clamping area is not impaired. Furthermore, the clutches (15, 16) acting on the underside of the lower mold parts (2.2, 3.2) facilitate the change of the blow molding tool. Finally, the figures show that the production space for the hollow bodies is not restricted by the actuators (13, 14). FIGS. 4-6 show a second embodiment of the closing unit (1) for a blow molding machine with a blow molding tool, the structure of which largely corresponds to the closing unit (1) according to FIGS. 1-3. Corresponding components and assemblies of the second embodiment are provided with the same reference symbols. There are differences from the first embodiment in that the first actuator (13) moves synchronously with the first mold carrier (4) and the second actuator (14) moves synchronously with the second mold carrier (5). In the representations according to FIGS. 4-6, the tool halves (2, 3) have not been shown in order to be able to better represent the components required for the synchronous movement.

As in the first embodiment, the closing unit (1) has a base frame which has side cheeks (9) arranged parallel to one another and at the upper edge of which a longitudinal guide (8) is arranged. The first and second mold carriers (4, 5) and the drive (7) are connected to guide elements which are slidably arranged on the longitudinal guides (8).

In order to synchronize the movement, it is provided that the first actuator (13) and the second actuator (14) are also movably arranged along the already existing fixed longitudinal guides (8) on the closing unit (1) and a first coupling (19) controls the movement of the first mold carrier (4) to the first actuator (13) and a second coupling (20) transmits the movement of the second mold carrier (5) to the second actuator (14). To move the first and second actuator (13, 14) along the longitudinal guides (8), a first and a second bracket (21, 22) are provided. Either of the two consoles

(21,22) is provided on the outer edges with guide elements, which are arranged displaceably on the longitudinal guides (8) arranged at a parallel spacing. The first actuator (13) is fastened in the middle of the first bracket (21) and the second actuator (14) is fastened in the middle of the second bracket. The first coupling (19) comprises two profile pieces which are fastened on the one hand to the first mold carrier (4) and on the other hand to the outer edges of the first bracket (21). The second coupling (20) also comprises two profile pieces which are fastened on the one hand to the second mold carrier (5) and on the other hand to the outer edges of the second bracket (22).

If the mold carriers (4, 5) now move in the first direction of movement (17), the first and second brackets become

(21,22) moves synchronously with it, so that the on the consoles

(21,22) attached actuators (13,14) are always below the mold lower parts (2.2, 3.2).

The first actuator (13) and the second actuator (14) can each be detachably connected to the underside of the associated lower mold part (2.2, 3.2) via the switchable coupling (15, 16).

FIGS. 7-9 show a third embodiment of the closing unit (1) for a blow molding machine with a blow molding tool, the structure of which is largely the same as that of the closing unit according to FIGS. 1-3. Corresponding components and assemblies of the third embodiment are with the same reference numerals. There are differences from the first embodiment in that the first actuator (13) moves synchronously with the first mold carrier (4) and the second actuator (14) moves synchronously with the second mold carrier (5). In the representations according to FIGS. 7-9, the tool halves (2, 3) have not been shown in order to be able to better represent the components required for the synchronous movement.

As in the first embodiment, the closing unit (1) has a base frame which has side cheeks (9) arranged parallel to one another and at the upper edge of which a longitudinal guide (8) is arranged. The first and second mold carriers (4, 5) and the drive (7) are connected to guide elements which are slidably arranged on the longitudinal guides (8).

In order to synchronize the movement, it is provided that the first actuator (13) and the second actuator (14) are movably arranged on the closing unit (1) along additional stationary longitudinal guides (23). The stationary longitudinal guides (23) are arranged parallel to each other in the space between the side walls (9) and the frame elements (6) on a support structure (24) which is attached to the base frame of the closing unit (1) at the bottom.

The first coupling (19) transfers the movement of the first mold carrier (4) to the first actuator (13) and the second coupling (20) transfers the movement of the second mold carrier (5) to the second actuator (14). In order to move the first and second actuator (13, 14) along the additional longitudinal guides (23), a first and a second guide car (25, 26) are provided, which are slidably guided on the parallel spaced apart additional longitudinal guides (23) are. The first actuator (13) extends from the first guide carriage (25) vertically upwards and the second actuator (14) extends from the second guide carriage (26) vertically upwards. The first coupling (19) comprises an angle profile, which on the one hand on the first

Mold carrier (4) and on the other hand is attached to the first actuator (13). The second coupling (20) comprises an angle profile which is fastened on the one hand to the second mold carrier (5) and on the other hand to the second actuator (14).

If the mold carriers (4, 5) move in the first direction of movement (17), the actuators (13, 14) arranged on the guide carriages (25, 26) are also moved synchronously. The first actuator (13) and the second actuator (14) can each be detachably connected to the underside of the associated lower mold part (2.2, 3.2) via the switchable coupling (15, 16).

List of reference symbols

1 clamping unit

2 mold half

2.1 Upper part of the mold

2.2 Lower part of the mold

3 mold half

3.1 Upper part of the mold

3.2 Lower part of the mold

4 First mold carrier

5 Second mold carrier

6 frame elements

7 drive

8 longitudinal guide

9 sidewalls

10 Synchronization device

11 mounting bracket

12 mounting bracket

13 First actuator

14 Second actuator

15 clutch

16 clutch

17 First direction of movement

18 Second direction of movement

19 First belt

20 Second belt

21 First console

22 Second console

23 Additional longitudinal guide

24 supporting structure

25 First guide carriage

26 Second guide carriage

Claims

Patent claims: 1. Closing unit (1) for a blow molding machine with a first and second mold carrier (4,5) and a blow molding tool with two tool halves (2,3) arranged on the closing unit, each tool half (2,3) on one of the two mold carriers ( 4,5) is releasably attached and has an upper mold part (2.1,3.1) and a lower mold part (2.2,3.2), the two tool halves (2,3) between an open state and a closed state in a first direction of movement (17) back and forth are movable, the lower mold part (2.2,3.2) of each tool half (2,3) relative to the upper mold part (2.1,3.1) of each tool half (2,3) in a second direction of movement (18) different from the first direction of movement (17) between an open state and a closed state by means of at least one first or at least one second actuator (13, 14) can be moved back and forth and the blow molding tool in the closed state of the two tool halves (2,3) delimits a mold cavity with undercuts if the two lower mold parts (2.2,3.2) are also in the closed state, characterized in that the at least one first actuator (13) and the at least one second actuator (14) are arranged on the clamping unit and one of the two lower mold parts (2.2) is detachable with an output of the at least one first actuator (13) and the other of the two lower mold parts (3.2 ) is releasably connected to an output of the at least one second actuator. 2. Closing unit according to claim 1, characterized in that the at least one first actuator (13) and the at least one second actuator (14) are movably arranged on the closing unit in the first direction of movement (17). 3. Closing unit according to claim 1 or 2, characterized in that the at least one first actuator (13) moves synchronously with the first mold carrier (4) and the at least one second actuator (14) moves synchronously with the second mold carrier (5) . 4. Closing unit according to claim 2 or 3, characterized in that the at least one first actuator (13) is arranged on the first mold carrier (4) and the at least one second actuator (14) is arranged on the second mold carrier (5). 5. Closing unit according to claim 4, characterized in that on the first mold carrier (4) one Fastening bracket (11) for fastening the at least one first actuator (13) and a fastening bracket (12) for fastening the at least one second actuator (14) is arranged on the second mold carrier (5). 6. Closing unit according to claim 2 or 3, characterized in that the at least one first actuator (13) and the at least one second actuator (14) are movably arranged on the closing unit (1) along at least one stationary longitudinal guide (8, 23), a first coupling (19) transfers the movement of the first mold carrier (4) to the at least one first actuator (13) and a second coupling (20) transfers the movement of the second mold carrier (5) to the at least one second actuator (14). 7. Closing unit (1) according to one of claims 1 to 6, characterized in that the at least one first and the at least one second actuator (13,14) arranged below the lower mold parts (2.2,3.2) and releasably connected to the underside of the respective lower mold part (2.2,2.3) are connected. 8. Closing unit according to one of claims 1 to 7, characterized in that the closing unit (1) has a fixed guide (8) along which the first and second mold carriers (4, 5) are displaceably guided. 9. Closing unit according to claim 6 and 8, characterized in that the actuators (13, 14) are movably arranged on the closing unit (1) along the stationary longitudinal guide (8) for the two mold carriers (4, 5). 10. Closing unit according to one of claims 1 to 9, characterized in that the releasable connection between the at least one first actuator (13) and one of the two lower mold parts (2.2) and the at least one second actuator (14) and the other of the two lower mold parts (3.2) each has a coupling (15, 16) which is set up for the transmission of forces between the actuator (13, 14) and the lower mold part (2.2, 3.2) at least in the second direction of movement (18). 11. Closing unit according to claim 10, characterized in that the coupling is a switchable, non-positive or positive coupling (15, 16). 12. Closing unit according to one of claims 1 to 11, characterized in that each actuator (13, 14) is a linear drive or a crank mechanism. 13. Closing unit according to one of claims 1 to 12, characterized in that the first direction of movement (17) is perpendicular to the second direction of movement (18).